/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Copyright (C) 2012-2018 OpenFOAM Foundation
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.

    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.

\*---------------------------------------------------------------------------*/

#include "v2f.H"
#include "fvOptions.H"
#include "bound.H"

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

namespace Foam
{
namespace RASModels
{

// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //

template<class BasicTurbulenceModel>
tmp<volScalarField> v2f<BasicTurbulenceModel>::Ts() const
{
    return max(k_/epsilon_, 6.0*sqrt(this->nu()/epsilon_));
}


template<class BasicTurbulenceModel>
tmp<volScalarField> v2f<BasicTurbulenceModel>::Ls() const
{
    return
        CL_*max(pow(k_, 1.5)
       /epsilon_, Ceta_*pow025(pow3(this->nu())/epsilon_));
}


template<class BasicTurbulenceModel>
void v2f<BasicTurbulenceModel>::correctNut()
{
    this->nut_ = min(CmuKEps_*sqr(k_)/epsilon_, this->Cmu_*v2_*Ts());
    this->nut_.correctBoundaryConditions();
    fv::options::New(this->mesh_).correct(this->nut_);

    BasicTurbulenceModel::correctNut();
}


// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //

template<class BasicTurbulenceModel>
v2f<BasicTurbulenceModel>::v2f
(
    const alphaField& alpha,
    const rhoField& rho,
    const volVectorField& U,
    const surfaceScalarField& alphaRhoPhi,
    const surfaceScalarField& phi,
    const transportModel& transport,
    const word& propertiesName,
    const word& type
)
:
    eddyViscosity<RASModel<BasicTurbulenceModel>>
    (
        type,
        alpha,
        rho,
        U,
        alphaRhoPhi,
        phi,
        transport,
        propertiesName
    ),
    v2fBase(),

    Cmu_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "Cmu",
            this->coeffDict_,
            0.22
        )
    ),
    CmuKEps_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "CmuKEps",
            this->coeffDict_,
            0.09
        )
    ),
    C1_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "C1",
            this->coeffDict_,
            1.4
        )
    ),
    C2_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "C2",
            this->coeffDict_,
            0.3
        )
    ),
    CL_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "CL",
            this->coeffDict_,
            0.23
        )
    ),
    Ceta_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "Ceta",
            this->coeffDict_,
            70.0
        )
    ),
    Ceps2_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "Ceps2",
            this->coeffDict_,
            1.9
        )
    ),
    Ceps3_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "Ceps3",
            this->coeffDict_,
            -0.33
        )
    ),
    sigmaK_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "sigmaK",
            this->coeffDict_,
            1.0
        )
    ),
    sigmaEps_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "sigmaEps",
            this->coeffDict_,
            1.3
        )
    ),

    k_
    (
        IOobject
        (
            IOobject::groupName("k", alphaRhoPhi.group()),
            this->runTime_.timeName(),
            this->mesh_,
            IOobject::MUST_READ,
            IOobject::AUTO_WRITE
        ),
        this->mesh_
    ),
    epsilon_
    (
        IOobject
        (
            IOobject::groupName("epsilon", alphaRhoPhi.group()),
            this->runTime_.timeName(),
            this->mesh_,
            IOobject::MUST_READ,
            IOobject::AUTO_WRITE
        ),
        this->mesh_
    ),
    v2_
    (
        IOobject
        (
            IOobject::groupName("v2", alphaRhoPhi.group()),
            this->runTime_.timeName(),
            this->mesh_,
            IOobject::MUST_READ,
            IOobject::AUTO_WRITE
        ),
        this->mesh_
    ),
    f_
    (
        IOobject
        (
            IOobject::groupName("f", alphaRhoPhi.group()),
            this->runTime_.timeName(),
            this->mesh_,
            IOobject::MUST_READ,
            IOobject::AUTO_WRITE
        ),
        this->mesh_
    ),
    v2Min_(dimensionedScalar("v2Min", v2_.dimensions(), small)),
    fMin_(dimensionedScalar("fMin", f_.dimensions(), 0.0))
{
    bound(k_, this->kMin_);
    bound(epsilon_, this->epsilonMin_);
    bound(v2_, v2Min_);
    bound(f_, fMin_);

    if (type == typeName)
    {
        this->printCoeffs(type);
    }
}


// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

template<class BasicTurbulenceModel>
bool v2f<BasicTurbulenceModel>::read()
{
    if (eddyViscosity<RASModel<BasicTurbulenceModel>>::read())
    {
        Cmu_.readIfPresent(this->coeffDict());
        CmuKEps_.readIfPresent(this->coeffDict());
        C1_.readIfPresent(this->coeffDict());
        C2_.readIfPresent(this->coeffDict());
        CL_.readIfPresent(this->coeffDict());
        Ceta_.readIfPresent(this->coeffDict());
        Ceps2_.readIfPresent(this->coeffDict());
        Ceps3_.readIfPresent(this->coeffDict());
        sigmaK_.readIfPresent(this->coeffDict());
        sigmaEps_.readIfPresent(this->coeffDict());

        return true;
    }
    else
    {
        return false;
    }
}


template<class BasicTurbulenceModel>
void v2f<BasicTurbulenceModel>::correct()
{
    if (!this->turbulence_)
    {
        return;
    }

    // Local references
    const alphaField& alpha = this->alpha_;
    const rhoField& rho = this->rho_;
    const surfaceScalarField& alphaRhoPhi = this->alphaRhoPhi_;
    const volVectorField& U = this->U_;
    volScalarField& nut = this->nut_;
    fv::options& fvOptions(fv::options::New(this->mesh_));

    eddyViscosity<RASModel<BasicTurbulenceModel>>::correct();

    volScalarField divU(fvc::div(fvc::absolute(this->phi(), U)));

    // Use N=6 so that f=0 at walls
    const dimensionedScalar N("N", dimless, 6.0);

    const volTensorField gradU(fvc::grad(U));
    const volScalarField S2(2*magSqr(dev(symm(gradU))));

    const volScalarField G(this->GName(), nut*S2);
    const volScalarField Ts(this->Ts());
    const volScalarField L2(type() + ":L2", sqr(Ls()));
    const volScalarField v2fAlpha
    (
        type() + ":alpha",
        1.0/Ts*((C1_ - N)*v2_ - 2.0/3.0*k_*(C1_ - 1.0))
    );

    const volScalarField Ceps1
    (
        "Ceps1",
        1.4*(1.0 + 0.05*min(sqrt(k_/v2_), scalar(100.0)))
    );

    // Update epsilon (and possibly G) at the wall
    epsilon_.boundaryFieldRef().updateCoeffs();

    // Dissipation equation
    tmp<fvScalarMatrix> epsEqn
    (
        fvm::ddt(alpha, rho, epsilon_)
      + fvm::div(alphaRhoPhi, epsilon_)
      - fvm::laplacian(alpha*rho*DepsilonEff(), epsilon_)
     ==
        Ceps1*alpha*rho*G/Ts
      - fvm::SuSp(((2.0/3.0)*Ceps1 + Ceps3_)*alpha*rho*divU, epsilon_)
      - fvm::Sp(Ceps2_*alpha*rho/Ts, epsilon_)
      + fvOptions(alpha, rho, epsilon_)
    );

    epsEqn.ref().relax();
    fvOptions.constrain(epsEqn.ref());
    epsEqn.ref().boundaryManipulate(epsilon_.boundaryFieldRef());
    solve(epsEqn);
    fvOptions.correct(epsilon_);
    bound(epsilon_, this->epsilonMin_);


    // Turbulent kinetic energy equation
    tmp<fvScalarMatrix> kEqn
    (
        fvm::ddt(alpha, rho, k_)
      + fvm::div(alphaRhoPhi, k_)
      - fvm::laplacian(alpha*rho*DkEff(), k_)
     ==
        alpha*rho*G
      - fvm::SuSp((2.0/3.0)*alpha*rho*divU, k_)
      - fvm::Sp(alpha*rho*epsilon_/k_, k_)
      + fvOptions(alpha, rho, k_)
    );

    kEqn.ref().relax();
    fvOptions.constrain(kEqn.ref());
    solve(kEqn);
    fvOptions.correct(k_);
    bound(k_, this->kMin_);


    // Relaxation function equation
    tmp<fvScalarMatrix> fEqn
    (
      - fvm::laplacian(f_)
     ==
      - fvm::Sp(1.0/L2, f_)
      - 1.0/L2/k_*(v2fAlpha - C2_*G)
    );

    fEqn.ref().relax();
    fvOptions.constrain(fEqn.ref());
    solve(fEqn);
    fvOptions.correct(f_);
    bound(f_, fMin_);


    // Turbulence stress normal to streamlines equation
    tmp<fvScalarMatrix> v2Eqn
    (
        fvm::ddt(alpha, rho, v2_)
      + fvm::div(alphaRhoPhi, v2_)
      - fvm::laplacian(alpha*rho*DkEff(), v2_)
      ==
        alpha*rho*min(k_*f_, C2_*G - v2fAlpha)
      - fvm::Sp(N*alpha*rho*epsilon_/k_, v2_)
      + fvOptions(alpha, rho, v2_)
    );

    v2Eqn.ref().relax();
    fvOptions.constrain(v2Eqn.ref());
    solve(v2Eqn);
    fvOptions.correct(v2_);
    bound(v2_, v2Min_);

    correctNut();
}


// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

} // End namespace RASModels
} // End namespace Foam

// ************************************************************************* //
